Automatic tension system for fueling at sea



June 17, 1958 J. C. PATTERSQN, JR

AUTOMATIC TENSION SYSTEM FOR FUELING AT SEA Filed Nov. 4. 1953 6Sheets-Sheet 1 INVENTOR ATTORNEYS June 17, 1958 J. c. PATTERSON, JR2,839,021

AUTOMATIC TENSION. SYSTEM FOR FUELING AT SEA 6 Sheets-Sheet 2 Filed NOV.4, 1953 I 1V VEN l' 0R Josq Paliemolm/Z ATTORNEYS June 17, 1958J.c;'PA1rERsoN,JR 2,839,021

AUTOMATIC TENSION SYSTEM' FORFUELING AT SEA Filed Nov. 4, 195s f@sheets-sheet :s

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ATTORNEYS June 17, 1958 .1. c. PATTERSON, JR 2,839,021

AUTOMATIC TENSION SYSTEM FOR FUELING A'r SEA Filed Nov. 4, 1953 6Sheets-Sheet 4 INVENTOR ATTORNEYS mM/@www June 17, 1958 .1. c.PATTERSON, JR 2,839,021

AUTOMATIC TENSION SYSTEM FOR `FUELING AT SEA I Filed Nov. 4, 1953 6Sheets-Sheet 5 CGN TRO/ STAT/0N ATTORNEYS i June 17, 1958 J. c.PATTERSON, .1R 2,839,021

AUTOMATIC TENSION SYSTEM FOR FUELING AT SEA 6 Sheets-Sheet 6 Filed Nov.4, 1953 AUTOMATIC TENSION SYSTEM FOR FUELING AT SEA Joseph C. Patterson,Jr., Falls Church, Va.

Application November 4, 1953, SerlalNo. 390,227

7 Claims. (Cl. 114-55) This' linvention relates to the transfer ofmaterial from ship to ship or from ship to shore as is involved infueling atsea. In fueling at. sea a cable is run between the tanker andthe ship being fueled and a hose is suspended from this line. Since bothships are subject to wave action, it is apparent that the tension on thesupporting cable is subject to large and sudden variation. These changesin tension cannot be allowed either to overstretch or overslack thecable or to impose strain upon the hose supported thereby. Large'` andsudden variation in cable 'tension imposes very high horsepower demandsupon. whatever equipment is used to remove tension and slack and, toprovide the .needed horsepower on a tanker, has been a` major problemparticularly with the advent of simultaneous fueling of several shipsfrom the same` tanker.

lt isv .therefore an object of thisinvention to maintain proper tensionon the hose supportingcable of a ship to ship refueling rig in a .fullyautomatic manner well within thel range of reasonable horsepowercapacity of. tanker power plants.

According to the present invention it. is proposedj in simultaneousfueling, to use the energy produced in thatpart of the roll cycle whenthe tanker and one of the ships move apart to assist in meeting. theload of. slack removal caused by roll of the tanker 'and another of. theships toward one another.

In particular it is an vobject of this invention to store or use theenergy produced from: roll of a ship away' from the tanker in anaccumulator arrangementI of large eapacity but of very high sensitivityso that responses are instantaneous and free from time lags caused byuncharged-lines,l vequipment inertia or friction.

Other objects and advantages of. this invention will be apparent fromthe following detailed description of several.v embodiments 'thereof .inconjunction with the 'annexed drawings wherein:

Figure l .is a schematic view .in elevation showing a central tankersimultaneously fueling a ship yon each side;

' Figure v2 is a hydraulic layout .showing the operating circuit forcontrolling the lines between the tanker and oneshi-p;

Figure -3 .is a view in vertical section of a vfour way valve forcontrolling a winch driving hydraulic B end, the valve Ibeing showninneutral position;

i .Figure 4 is a view of the valve of Figure' 3 in haulingin andautomatic tensioning position;

. Figure 5 is a view of the valve ofvFigure '3 in payingoutV position;

Figure 6 is a view in vertical section of a pressure relief valve of thetype used vin the ksystem of Figure' 2; Figure 7 is a view .in verticalsection of a iiow controlA valve 'of the type used in thesystem :ofFigure .2;

,- Figure 8 is a view in vertical section of a 'pressure' reducing valveof the type used in the system of Figure 2;

Figure 9 is a hydraulic layout similar to that of Figure 2 butshowingan. arrangement for 'charging accumulators in a manner to vary thepressure delivered thereby;

2,839,021 Patented June 17, 1958 Figure 10 is a. view in. verticalsection of a modied pressure compensator pilot valve of the type used inthe system of Figures 9, 1l andk 12;

Figure l1 is another hydraulic layout similar to that of 'Figure 2 whichshows' another scheme for varying the accumulator pressure;

Figure 12. is still another hydraulic layout similar to that. of Figure2v but Vshowing a further modiii'ed scheme for varying accumulatorpressure;

Figure 13 is a view partly'in side elevation and partly in. section of acontrol valve used with the arrangement of Figure 12; and.

Figure 14 is a. fragmentary top plan view of the control valve of Figure13.

Referringnow tozFigure 1, a tankerequipped according to the 'presentinvention is designatedA by the reference character' T while the shipsbeing fueled are designated S-l'and S-Z. During fueling, a cable 10 isrigged between the tanker T, the' movable supply, and the ship S-l and arsimilar line. 11 is rigged between the tanker T andthe ship S2,4 shipsS-1 and S-Z being the movable use media. Saddles 12 and 13 supportedoutboard of the tanker T from the cables 1i) and 1,1, respectively,function to support fueling hoses 14 and 1S, respectively. Theriggingsbetween the movable supply, tanker T, and the movable. use media, shipS-1 and ship S-2, are each horizontally supported from the deck oftanker T by Xed vertically 'extending king posts 10a and 11a. In placeof king posts, however, booms, which can be pivotally supported `andguyed into place, can be used to support the riggin'gs. The position ofthe outboard saddles is controlled by cables 16 and '17, respectively.Inboard sad- -dles 18 and` 19 are supported and positioned by cables Zlandi 21,V respectively. Cables 10, 11, 116, 17, 20 and 21 are controlledby separate Winches 23, 23a, 30, 30a, 3S and 35a which" are carried onvthe deck of tanker T, -the movable supply. These winches and theiroperation will be apparent from Figure2 in which ythe machinery foroperating the cables 10, 16 and 20' is shown in detail.

'Beforefdescribing Figure 2 it will be well to note that the arrangementshown in regard to cables 10, 1-6V and 20 i's repeated on theother sideof the ship for cables 11, 17 and 21. Furthermore, even thoughonly twofueling stations on ship T are shown, there may be various numbers ofVsuch stations depending upon the sizeof the ship. There is, however,advantage in having an even number of fueling' stations equallydistributed on opposite sidesv of the ship as will hereinafter morefully appear. The equipment on the shipsv S-l and S-2 forms no part ofthe present invention since all controls` on the lines are maintainedfrom the tanker T. In general the ships being fueled which is them-ovable usek media will have some sort of cable attachment structuresto receive Vthe cables- 10 and 11. One ytype is schematically indicatedin Figure 1 over a sheave 2'2- 'to a winch 23 which is driven throughgears 24, 25, 26 and 27 from the B end 28 of a hydraulic transmissionwhich is a hydraulic motor-pump unit. Cable 16 passes overa sheave '29to a winch 30 which is connected to a planetary type diierentiall gearsystem 31. The planets of the diierential system `are connected to` theB end 32 of a 'hydraulic transmission while the sun. gear of thedilerential. system 31 is connected through a gear 33 lto the gear 24 on`the shaft of winch /23 in .y a manner to cause a 1:1 speed ratiobetween the drums s, j 20 and winch 35.*which are arranged with thewinch 3'5v urging cable 20 in the direction of take-up, the saddle FromFigure 2 it will be seen that the cable 10 'passes' 18 is'pulled againstthe bracket 110 of sheave '34 and maintained in this position until aforce is exerted on saddle 18 by hose 14 suticient to overcome the pullby cable 20. When this predetermined tension in hose 14 occurs, the hose14 will y,function to cause cable 20 to override and pay out thus movingsaddle 18 away from sheave bracket 110' and relieving the excesstensionin hose 14 until such time as an equilibrium will be established betweenthe tension on hose 14 and the tendency of cable 20 to take-up. When thetension. on hose 14 falls below the predetermined tension, the Winch 35will act to take-up cable 20 until saddle 18 rests against sheavebracket 110'. f

The hydraulic transmissions that include driven or B ends of thehydraulic motor-pump units 28, 32 and 37 in# clude a single pumping or Aend 38. is driven directly or througha 'gearebox 39- by a prime moversteam turbine 40. Pressure liquid is'also supplied to the B endsfromaccumulators 41 and'v 42. Before describing the supply ofp'ressurevliquid to the B ends and the controls imposed thereon, it is well tonote .that the B ends 28, 32 and 37 which are capable. of acting asmotor units for driving Winches 23, 30 and 35, respectively, when highpressure liquid' from the accumulators is permitted to ow to thewinches,and as pumps to pump fluid under pressure into. the 'high` pressure sideof the accumulators when torsional load is applied to the winches andthe Aend 38 'are not 'shown in detail herein since they are hydraulicpiston and cylinder units of the well known type, typical specimens ofwhich are fully shown in Patent 2,554,381. y The A end 38 is of theadjustable tilt plate type shown in the said patent. i n

The description of the operation of the circuit of Figure 2 will becommenced under the assumed conditin that the lines 10 and 11 arealready rigged and that the equipment is operating normally to keep themproperly tensoned. After introducing the various structural parts intheir performance of this function, the operation of the same partsduring rigging and under emergency conditions will be discussed.

When the liquid tlow to and from the B end 28 is as indicated by thearrows in Figure 2, the B end is turning the winch 23 in a cable haulingin direction. When the ship and tanker roll apart, the B end 28 isoverhauled and the direction ofthe liquid ow is opposite to that shownin Figure 2. When the ow is as shown in Figure 2, high pressure liquidis supplied through conduit 44 which is connected through conduit 45 tothe high pressure main 46 leading into the high pressure chambers ofaccumulators 41 and 42, for example, chamber 43 of accumulator 41. Highpressure main 46 This A end is also connectedV to a feed line 47 fromthe A end 38 I of the system. The high pressure liquid supplied to theconduit 44 passes through a flow control valve 87 of the type shown inFigure 7 and enters a 4-way reversing valve 49 shown in considerabledetail in Figures 3, 4 and 5. With the valve 49 in the Figure 4position, the pressure liquid from conduit 44 enters at chamber 50 andpasses through a gate 51, the valve housing space 52 and a gate' 53 tochamber 54, which is connected by pipe 55 to the B end 28.

Working liquid returning from the B end 28 passes through a conduit 56into the chamber 57 of the valve 49, again see Figure 4, and from thechamber 57 flows through gate 58 and valve body space 52 to manifoldedchamber 59. Chamber 59 is connected by conduit 60 to low pressureconduit 61 which is, in turn, connected to the low pressure side ofaccumulators 41 and 42 by the line 62. Y

When the ships roll apart while the valve 49 is in the Figure 4position, the winch 23 is driven Iby the cable 10 which reverses the Bend 28 against the force of the pressure uid. This converts the B vend`28 into a pump and causes it to pump liquid through the line 55,

through the-valve 49 into line 44,'through check valve 48 and through avalve 110 and line 45 to the high pressure side of the accumulators 41and 42. This, of course, charges the accumulators and stores energywhich can be used later in the roll cycle of the ships when thehaulingin operation is again required to keep the cables 10 and 20adequately taut.

If now reference is again made to Figure 1, it can be seen that whenships Tand S-1 are rolling away from one another so that B end 28 ischarging the accumulators, the B end which operates cable 11 is requiredto haul-in. Some of the horse power requirements of this action on thecable 11 can helmet by the energy delivered through B end 28. The B endwhich operates cable 11 is operatively connected to the accumulators 41and 42 arranged in parallel through conduit 46. `Since the structure isthe same for both sides of the ship, the B end systemV servingcable 11is not shown but the conduits whichconnect ltofit are shown in Figure 2at A63' and 64. It can be seen that with simultaneous fueling the tankeris always rolling Vaway from a ship or ships on one side of it andtoward a ship or ships on the other side of it.V Thus the B end or endswhich vare beingroverhauled are pumping fluid into the system at thevery moment when-.the Bends which'are hauling in, l

need the working iluid.v This greatly reduces the' Arnak'e up liquidrequired to keep the accumulators charged and hence reduces the-load onvthe tankers power supply.) vUpon reference to Figures 3, 4 and 5, thedetails ofA valve 49as well as valves 70 and 71 can ber understood. Itwill be seen that the valve body space 52 of the valve 49 is generallycylindrical in shape and is subdivided Y axiallyl by pistons 65, 66 and67 fixed in spaced relation along an operating shaft 68. As has beenexplained, when the shaft 68 is in the Figure 4 position, chambers 50and 54 are interconnected and so are chambers 57 and 59. This-is theposition for either hauling-in or automatic operation. On the otherhand, during rigging, when the line 10 is initially payed out, valve 49is set to the Figure 5 position. In this position pressure liquid enterschamber 50 and leaves through chamber 57, being delivered to B unit 28through the conduit 56. Working liquid returning from the B end 28through conduit 55 enters valve 49 at chamber 54 and leaves throughchamber 59 to low pressure line 60.

During the time that accumulators 41 and 42 are initially charged, whichis before the line 10 is payed out, the valves 49, 70 and 71 are set toa neutral position shown in Figure 3 in which flow to and from B ends28, 32 and 37 is blocked by pistons 65, 66 and 67. Once the accumulatorsare charged, by the pumping action of the A end 38 delivering to thesystem from liquid storage reservoir 69 through line 47, the line 10 maybe payed out. Thus, when the line 10 is connected to ship S-1, thesystem is made ready for automatic tensioning by gradually transferringvalve 49 from the Figure 5 to the Figure 4 position.

Thus far nothing has been said regarding B ends 32 and 37. It should benoted, however, that the valve 70 is exactly like valve 49 except thatit controls B end 37 and that valve 71, also exactly like valve 49,controls B end 32. The low pressure working liquid line 61 is directedinto valve 71 by branch conduit 111 and into valve 70 by branch conduit72. The high pressure liquid is directed into the valves by lines 111'and 72.

Once the line 10 is in position between the tanker and the ships to befueled and the hose is in saddle 12 and 18, valve 70 is adjusted to thehaul in position to lift the `hose 14 to the Figure l position. Valve 70remains in haul-in position and the saddle 18 is pulled up hard againstsheave bracket 110'. The position of saddle 12 is adjusted on line 10 bymanipulating valve 71. When outboard saddle is in the right position,the valve 71 is set to neutral, Figure 3, position, whereby to lock theplanets of differential 31. This causes the automatic gesegnetcompensations of `B end 28 to adjustWinches- 23 and' 30 'simultaneouslyand in 'synchronisnr `SinceB end 32 is used only in saddle positioning,'it is much smaller than B end 28 and B end 23 can easily resist anytorque input from B end 32. Accordingly, manual adjustments of thesaddle 12 are possible while B end 28 isoperating, it' being apparentthat movement of the diierential planets will add or subtract from themovement imparted to gear 33, the desired direction being achieved bysuitable positioning7 of valve 71. Note that since gears 24 and 33 mesh,vthey will move in opposite directions -whereby the reversal in thediiiierential will serve to bring winch 3d back to the same direction aswinch 23. Hence when valve 7l is locked in neutral and valve 49 lockedto 'the automatic or Figure 4 position, saddle 12 will be payed out whenline 10 is being pulled out and saddle y12 will be` retrieved when line.10 is `being hauled in.

Saddle 18 is separately controlled from B end 37 but the arrangement issuch that the valve 70 is set in the Figure 4 position so that thesaddle is hoisted up against sheave bracket 110. Saddle 13 is held thereand will not move unless the movement of the ships away from one anotherdemands more length of hose 14 in which case the torque of B ends 28 and37 will be overcome and cables and 2t) will be pulled out and cable V16will be payed out. Consequently, saddles 12 and 18 are allo-wed outboardmovement by the respective cables. This cable and saddle movement liftsmore hose outboard of the ship, to meet the roll apart condition toprevent imposing excessive tension strains on the hose. It can be seen'that hose is pulled out against the torque of B end 37, and hose isretrieved, when the ships roll toward each other, until the saddle4support cornes up hard against bracket 110.

The winches 23, 3i? and 35 have, of course, very different loads tocarry and their horsepower demands are quite different. It iscontemplated Vthat winch 23 demands 150 horsepower while winches 30 and35, respectively, require only 35 and 50 horsepower. This gives a peakhorsepower demand vof 235- but, due to the accumulators, the maximum lpeak demand from the ships power supply is 75 horsepower and the averagedemand is only 35 horsepower. This being the case, turbine 49 can bequite small compared to .the Itotal H. P. of the units. Net only do theaccumulators-41 and 42 'carry a considerable part of the horsepowerdemand, almost two-thirds at peak, but they also .have enough yreservecapacity to permit lines and hose to be retrieved without damage in caseof a power failure on f he tanker.

From the foregoing it is appreciated `that steam turbine 40 must have apeak capacity of 75 horsepower. The A end 3.8, which it drives, is ofthe variable delivery or stroke type, but it also drives a constantdelivery replenishing and servo pump 73. The servo pump 73 is drivenfrom the gear box 39 and it draws liquid from the reservoir as does theA end 38. The pump 73 is connected through conduit 74 to a relief valve75' which has an escape conduit 76 leading to reservoir 77. Pressureline 74 connects through conduit 78 to one way check ".alves 114 and 11Swhich allow the replenishing oil to enter either the high pressure orlow pressure side. This compensa-tes for leakage. The pump 73 keeps thelow pressure side of ythe system and accumulators at about 100 p. s. i.-so that the suction sides of the B lends 28, 32 and 37 are alwaysunderpressure which forces hydraulic liquid to the B ends thus avoidingshocks due to cavitation.

. Another highly important feature is the use of several accumulators inparallel. These accumulators, arranged.,

in parallel, have, individually, small pistons, but the ltotal capacityof the parallel group is large. If a single accumulator is used with asystem of the type described, a

minor demand Ifor pressure fluid may result in a time lagv 6 and 'surges'in accumulatorrpistorrrespense, but, y'with' several accumulators inparallel, the high 'horsepower capacity of a large accumulator isachieved together -With high sensitivity of one piston giving larger'movementsfor small liquid demands. The result is that both major andminor demands for working liquid are met with equal speed and withoutlarge piston friction drag and inertia shocks. The accumulators 41 and42 will be'rec'ognized as the dual piston type with both pistons fixedto and guided by a common central shaft. The vaccumulator 41 has a highpressure chamber 43 and a low pressure'chamber 43a. These chambers areconnected in parallel with like chambers of accumulator 42. Only twopiston accumulators are shown in the illustrations but it is 'evidentthat there could be any number connected in parallel.

It has been explained that the A end 38 is of the vari able stroke typein which the displacement per revolution can be varied from zero tomaximum by 'adjustment of the tilt plate. A pressure responsive device79 connected to high pressure line 47 adjusts the tilt plate ofthe A end38 to meet the demands of the system. An identical arrangement is shownapplied to the A end marked 69, which is shown in Figure 3 of Patent2,554,381 consti tuting a conventional and'well known arrangement which,per se, forms no part of the present invention. Suitable relief valvesare provided throughout `the system according to good prior artpractice. Only one of these is shown but a description of the structureand vfunction of it will afford an understanding of the ktype of lreliefvalves used. Figure 6 shows relief valve 75 in detail and from thatfigure the internal connections between lines 74, 76 and 78 can be seen.

If operation is normal, flow through the valve 7'5 is from right to leftas shown in Figure 6, i. e. opposite tothe direction of the arrows. `Ifback -pressure in line 78 becomes excessive, the `pressure throughorifices 80 and 81 will be sufficient to unseat ball l82 against spring83. Because of 'the `small diameter `of orifice l80, 'the pressure inannular chamber 84 will fallbelow the pressure of lines 74 and 78 withthe result that piston 85 will move upwardly and unseat its valve part86 whereby lines 74 to 78 are relieved through line'76.

It will be noted that 'the system of-Figure 2 is "prol vided with'maximum ow control valves 87 to :91, inelusive. Valve 87 is shown 'indetail in Figure v7 and a description of it will suice for'valves 88 to`91, inclusive, which are of identical construction. The housing ofvalve 87 is provided with opposite ports l92 and *93 for con-f nectionacross the .high pressure line 44 lleading to valve 49. VIn the line 44between the connections to jports and r93 there is the check valve 48.The elect of the valve A48 is to make 'high pressure output'frorn theaccumulators flow through valve 87 while high pressure liquid deliveredfrom the B end 2S, Whenthe ships are .rolling apart, is made to ow vtoaccumulators or the high pressure line through valve 48. AFlow to the Bend 28 'is therefore metered and controlled to a maximum While` highpressure v'llow from it is not. Therefore valvev 87 prevents B end 28from overspeeding in case line 10 becomesdisconnected.

The liquid entering port 92 reaches port 93 `through a piston valve 94and an eccentric l95. The leccentric 95 defines an adjustable eccentricgroove 9'6' which 1is used to limit the rate of liquid discharge fromthe valve. The shaft 95 may be turned to different positions and lockedin place.` The rate of flow is maintained independently of operatingpressure variations by interconr'iectingV the chamber 96 below the valve94 with 'the 'port 93 b'y a narrow channel 97 leading to piston chamberV'98 andi another narrow channel 99 leading from piston chamber 98 to'port 93, It is now evident that the pressure. in chamber`96 willalwaysbe the same as the static pressure which is produced by fthe `weight 'ofthe .piston `10`0 and' ,the compression ofthe spring 101., If thepressure in port 92 rises, -the piston 100 also will rise and close thevalve .94 until the rate of ow into chamber 96 is equal to that beingdischarged through groove 96'.

l 'The valves 88, 89, 90 and 91 are structurally and functionally the'same as valve 87. They are located, how-4 ever, inthe lines between LtheB ends 32 and 37 and their respective 4way valves 71 and 70 rather thanbetween the high pressure accumulators 41 and 42 and the 4-way valve 49as isthe case of ow control valve 87. Furthermore, as can be seen by theposition of check valves 92' to 95', inclusive, the flow control electedby valves 88 to 91, inclusive, is in regard to liquid deliveredfrom'rather than to the B ends 32 and 37. This limits the maximum speedof the B ends for both haul-in and pay-out irrespective of which side ispressurized. As B ends 32 and '37 have overhauling loads, the '.owcontrol valvesv prevent overspeed in the pay-out direction as well as inthe haul-in direction. Speed control in the haul-in direction is neededin case a cable becomes disconnected.

Pressure reducing valves 96', 97 and 98' are employed in the system ofFigureZ and the details` of construction of these valves can beunderstood upon reference to Figure 8 which is described in conjunctionwith}valve 98 which is in the high pressure line 46 leading to 4-,wayvalve 71. It will be understood that pressure reducing valves 97 and 98are made necessary by the fact that the load borne by B ends 32 and37 ismuch less than that borne by B end 28 whereas the power and pressure ofthe system as a whole are calculated with the high load B end 28 inmind.

Pressure reducing valve 96' is ordinarily by-passed with stop valve 110open; however, for rigging the lines, a lower pressure than accumulatorpressure may be needed to obtain iine control of B end- 28. In such acase, valve 110 is closed which forces the oil to pass through thereducing valve 96' so that a lower predetermined pressurel is applied toB end 28.

The high pressure uid from the line 46 enters the valve 98' (Figure 8)at port 99' which leads into charnber 100' containing a piston 101 foractuating a valve 102 which controls ow from the chamber 100' to achamber 103. The liquid leaves chamber 103 and enters chamber 104 atreduced presesure. Chamber 104 is in communication with a ball valve 105and the upper part of chamber 100'. From chamber 104 the liquid ows tothe valve 71 through port 106. If the volume flowing through valve 102starts to become greater than is necessary to maintain the reducedpressure at port 106, pressure on the ball valve 105 will increase, theball valve 105 will be depressed against the thrust of spring 107 andsome liquid will drain from relief port 108. If the volume owing through.valve 102 is greater than the combined discharge from ports 106 and108, the pressure in chamber 103 Will rise causing piston 101 to bedepressed partly closing valve 102. The connections from the reliefports 108 of the valves 96', 97' and 98 are not shown in Figure 2 but itis to be understood that they return to the reservoir 77 by any suitableconnections known to the art.

The inboard saddle winch 35, after it has positioned the inboard saddle18, maintains a tension to prevent the hose 14 from beingoverstressed.During tensioning, the saddle y18 is pulled up against sheave bracket110. Hose is pulled out against the torque of B end 37 and hose ishauled-in when the ships roll toward one another until the saddlesupport comes up tight against the bracket 110'. Note that a check valve109 by-passes the pressure control valve 97 so that when the B end 37 ispumping, liquid is returned to the high pressure line 46 through valve109', by-passing valve 97.

In Figure 2, broken line connections 49a, 70a, and 71a to the valves 49,70 and 71 respectively indicate that those valves may be operated from aremote station 109 '8 if desired and convenient toa particular ship.Various modifications of the form of the invention here described willbe apparent to those skilled in the art and it is there fore intendedthat the scope of the invention be construed on the basis of theappended claims.

In Figure 2, the line 171 from the accumulator 41 leads to an ordinarybank of high pressure airflasks charged by any sort of compressor, notshown. It is possible, however, to vary the torque output of the Winches23,30 and 35 from a small amount to maximum by variation of the airpressure of the main accumulators. One way in which this may beaccomplished is by use of a remotely controlled pressure regulated aircompressor as shown in Figure 9. In Figure 9, parts which are the sameas parts shown in Figure 2 bear the same reference numerals and brokenaway pipes lead to the same parts as are more fully illustrated inFigure 2. In Figure 9, the association between the adjustment of the Aend and the adjustment of the air or gas pressure on the accumulator isshown.

The numeral 172 represents an air compressor, the output of which isconnected by a conduit 173 to the conduit 171 leading to accumulators 41and 42. Inter connected with the conduit 171 is a manifold 174 leadingto high pressure storage flasks 175. Conduit 173 also leads to an aircylinder 176, the details of which are shown in Figure l0. A connectionshown in broken lines at 177 leads to the control station 109 where anoperating handle 118 is disposed for -the purpose of adjusting theautomatic pressure setting of the compressor 172 by any known expedient,not shown.

The assembly shown in Figure l0 comprises a piston 119 biased by aspring 120 to the lowermost position. Piston 119 is connected by a rod121l to a tilt plate 122 of the A end 38. The spring 120 thus biases thetilt plate to maximum stroke. Below the piston 119 there is a workingspace which is connected by a line 123 with a valve 124. When pressureexists in the line 123 greater than that necessary to overcome thethrust of spring 120, the tilt of the tilt plate 122 is reduced and thestroke of the A end 38 is correspondingly reduced. Thus, when the liquidpressure in the line 123 is relatively low the stroke of the A end 38 isrelatively large and it is working at high capacity to make up thepressure deciency in the system. When the pressure in the system is highenough, that will be felt in the line 123 and the spring 120 will becompressed, whereby the A end will be stroked to neutral.

The valve 124 delivers pressure liquid to the line 123 so that theoperation described in the foregoing paragraph can take place. To thisend there is located within the valve 124 a plunger 125 having thereonan annular groove 126 leading to a central chamber 127 and an annulargroove 128 axially spaced from the groove 126. When pressure fluid isneeded in the high pressure lines of the system and A end 38 should beworking, the high pressure liquid comes from the high pressure line 46through a line 129 into a port 130 leading to groove 126 and chamber127. This liquid acts to bias the plunger to the left of its Figure l0position. It s biased to the right by a spring 131. As the pressure isbuilt up by the operation of the `A end eventually the pressure in thechamber 127 will be able to overcome the thrust of the spring 131 andthe plunger 125 will move to the left of its Figure l0 position. When itdoes so, the groove 126 will interconnect lines 129 and 123 whereby thehigh pressure from line 46 will be felt underneath the piston 119 andthe spring 120 will be compressed.

By the use of the air cylinder 176 the magnitude of the pressurenecessary to shift the plunger 125 can be adjusted. Thus piston 132 isconnected by a rod 133 to a piston 134 which acts on the spring 131. Airfrom the line 173 is admitted into working space 135 to the left ofpiston 132 whereby the piston can be moved to the right to increase theloading on spring 131 to increase the presasso-c21- 9 Sure necessaryinthe chamber- 127 to move -the plunger 125 to the left-to permitrestoration of the-piston rod'121 to the zero stroke position. Theconnections at 137,v 138, 139 and 140 are drains to sump tank 77.

It will be appreciated that the pump 172 will be equipped with anautomatic pressure regulator which will cut it olf when air pressure hasreached the value to which the regulator is set. The setting of theregulator is accomplished from station 118.

If more tension on the cables is required the regulator is set bystation 118 to a higher pressure. The air compressor pumps air into theair asks and accumulators. This increased pressure is automaticallyrellected in the high pressure oil so that piston 125 of valve 124 wouldbe displaced to the left if the higher air pressure was not also pipedto cylinder 176 via pipe 173 to act as an automatic pressure settingadjustment on valve 124 which controls the stroking of A end 38. Piston132 with its spring 135 is proportioned to automatically adjust thepressure setting of valve 124 as the air pressure is increased ordecreased. Accordingly if the regulator is set for less pressure thanexisting in the system an air drain off from the asks and accumulatorswould be necessary. This is accomplished by the regulator on thecompressor 172. As the air pressure is lowered this lower pressure isreflected in the high pressure oil so that the oil and air pressure arereduced together. Consequently Valve 124 is automatically set for thelower pressure and does not shift from whatever position it is in at thetime the air pressure is regulated. i The varrangement described inconnection with Figures 9 and 10 brings about variations in the pressuredilerence between the high and low pressure liquid lines by increasingthe air loading on the high pressure accumulators.A It is apparent,however, that the same result can be achieved by introducing andregulating an yair pressure on the air side of the low pressure pistonof the accumulators. This can be done either through a separateaccumulator piston as shown in Figure l1 or through the regular lowpressure piston as in Figure 12. In any case, the air pressure must bedelivered to the low pressure side of the accumulator through anadjustable reducing valve such as that shown in Figures 13 and 14. Thereducing valve of Figures 13 and 14 is generally indicated by areference character 141. In both of Figures 11 and 12 the air compressor172 is present as Well as the storage flasks 175. The compressor 172 isconnected by a conduit 142 to the accumulator 41. The gas storage asksare connected through a manifold 143 to the conduit 142 and the conduit142 is tapped by a line 144 which leads to the reducing valve 141. Thereduced pressure on the far side of the reducing valve 141 is deliveredin the case of Figure ll through a conduit 145 to an auxiliary cylinder146 containing therein a piston 147 mounted on a shaft 148 to move withthe main pistons of the accumulator. The line 145 is tapped at 149 andthe line 149 feeds to an A end control device 150 which is exactly likethe one shown in Figure except that the line 149 taps in at the pipemarked 136 in Figure l0 rather than at the pipe marked 173. In thiscase, 173 becomes a drain connection.

In the case of Figure l1 or 12 the high side air pressure on theaccumulators is not varied. It remains at a predetermined fixed value.The air compressor 172 is used only as a source of air to charge thehigh pressure side. The compressor is under automatic pressure regulatorcontrol to hold the predetermined pressure. Air pressure from the highside is piped via the pressure reducing valve 141 to opposite end of thepiston accumulators. In this way the elective air pressure on theaccumulators is regulated so that the tension on the cables can bevaried from a predetermined minimum to the maximum. By increasing theair pressure being delivered and heid by regulator 141- to theapposite-.end of the acoumulators the effective pressure' andJ-resultingoil pressure which dictates the output torque of the B ends is lowered.

The air pressure line 152 or v149 of Figures l1 and 12 respectively isconnected to line 136 of Figure :10. By this means the pilot valve shownin Figure 10 is biased so that it shifts over at a lower oil pressure asthe air pressure on the low pressure .piston accumulator is increased.

In Figure l2 the low pressure fluid is delivered through a conduit 151to the upper side of low pressure .piston in the accumulator 41. Line151 is tapped by aline 152 corresponding in function and structure toline 149 of Figure l1. The reducing valve 141 of Figures 13 and 14 isco-mprised of two ball valves 153 and 15'4 which are maintained a fixeddistance apart by an intervening rod 155. The ball valve 153 is urgedyby a spring 1'56 to seat on a plunger 157. The ball valve 154 isengageable with a seat in a plunger 158 mounted on a diaphragm 159 whichis biased to the left of the Figure 13 position by a spring 160. A cam161 acts against one end of the plunger 157, and the right side of thediaphragm 159 is vented to atmosphere. For a given pressure reductionthe cam is adjusted in such a way that plunger 157 is moved enough tounseat Yball 153 while ball 154 is seated. Under these conditions, airwill enter through the supply conduit, go past the ball y153 and exitthrough the chamber 162. As pressure builds up on the delivery side, theeffect will be to move the diaphragm 159 to the richt, ultimatelyunseating ball valve 154 and permitting the high pressure air 'to ventto atmosphere through the port 163. y

It is to be understood that the structure of valve 141 forms no part ofthe present invention, the valve shown being a Westinghouse Air BrakeCompany product as described in their Bulletin 10M-2 of March 1949. llnthe lcase of Figures 1l and l2, the cam L161 is adjustable by any knownmeans from a control station 164 located at a convenient part of theship through control line 164a.

What is claimed is:

l. A ship having a winch on each side, a cable extending from each Winchto a mass remote from each side of said ship, each winch maintaining itscable in a taut condition, a hydraulic motor-pump unit connected indriving relation to each winch, a high pressure accumulator, a lowpressure accumulator, conduits interconnecting said accumulators inparallel branches through each unit whereby when ship roll causes theunit on one side of the ship to pump and charge the high pressureaccumulator the other unit which is working at the same time isdischarging said high pressure accumulator and means to maintain thepressure in the high pressure accumulator at a predetermined value.

2. In equipment for supporting a load between relatively movable supplyand use media, winches supported by said media, a supporting cableoperatively connected to and controlled by one of said winches, saidsupporting cable extending between said supply and use media a loadsupporting mechanism depending from said supporting cable, a positioningcable connected to said loadsupporting mechanism and to another of saidWinches, a hydraulic motor unit connected to each winch, high and lowpressure accumulator means, means to charge said accumulator means to apredetermined value, means to control the pressure difference betweenthe high and low pressure sides of said accumulator means whereby toenable the tension on said cables to be varied, and selective means forinterconnecting said high and low pressure accumulator means in circuitwith each of said motor units.

3. The combination comprising a hydraulic motorpump unit, a variableload connected to said pump unit, a high pressure accumulator, a lowpressure accumulator, means connecting said motor-pump unit in serieswith said accumulators so that the high pressure accumulator suppliesthe liquid under pressure to drive the unit or receives pressure liquidfrom the unit depending upon whether it can overcome the load, means tomaintain the pressure in said accumulators above a predetermined minimumand means to control the pressure difference between said accumulators.

4. The vcombination comprising a winch, a hydraulic motor-pump unitconnected in driving relation to the winch, a high pressure accumulator,a low pressure accumulator, conduits interconnecting said accumulatorsthrough said unit whereby when the winch is under load the uid from thehigh pressure accumulator drives the unit and exhausts to the lowpressure accumulator and when the winch is load driven the unit pumpsliquid from-the low pressure accumulator to the high pressureaccumulator, a reservoir of operating uid, means connected to saidreservoir to maintain the pressure in the accumulators above apredetermined value, and means to control the pressure differencebetween said accumulators to enable the load carrying ability of saidwinch to be changed,

5. In equipment for supporting a load between relatively movable supplyand use media, Winches connected to said media, a supporting cablecontrolled by one of said Winches, said ysupporting cable extendingbetween said media, load supporting mechanism depending from saidsupporting cable, a positioning cable connected to said load-supportingmechanism and to another of -said Winches, a hydraulic motor unitconnected to each winch, pressure accumulators interconnected inparallel, a hydraulic pump unit, selective means to connect saidaccumulators in circuit with each of said motor units, automatic meansto cause operation of said pump unit to maintain said accumulatorscharged to a predetermined pressure, and means to control the effectivepressure in said accumulators whereby to enable the tension on saidcables to be varied.

6. A combination comprising a winch, a hydraulic motor-pump unitconnected in driving relation to the winch, a variable load on saidwinch whereby when said load is relatively large said winch drives saidunit and when said load is relatively small said unit drives said winch,a high-pressure accumulator for supplying and receiving liquid underpressure to and fromsaid unit, a low-pressure accumulator for collectingand supplying liquid from and to said unit, means interconnecting saidaccumulators through said unit whereby, when said unit drives saidwinch, the liquid from the high-pressure accumulator drives said unitand exhausts to the lowpressure accumulator and, when said winch drivessaid unit, the unit pumps liquid to the high-pressure accumulator, areservoir of operating liquid, and means connected to said reservoir andsaid accumulators to maintain the pressure in both the high-pressure andlow-pressure accumulators above a predetermined value.

7. The combination of claim 6 in which the high and low pressureaccumulators are of the piston and cylinder type each accumulatorcomprising a `piston and cylinder, the piston and cylinder of thehigh-pressure accumulator having the same displacement as that of thelow-pressure accumulator and means rigidly interconnecting the piston ofthe high-pressure accumulator to the piston of the low-pressureaccumulator.

References Cited in the file of this patent UNITED STATES PATENTS Re.20,551 Rouse Nov. 9, 1937 619,073 Deering Feb. 7, 1899 619,074 DeeringFeb. 7, 1899 1,296,669 Kuharchek Mar. 11, 1919 1,685,927 Miller Oct. 2,1928 .2,290,479 Mercier Tuly 21, 1942 2,479,316 Connelly Aug. 16, 19492,554,381 Patterson May 22, 1951 2,595,248 Greer et al. May 6, 1952

